drm/vmwgfx: Fix ACPI S3 & S4 functionality.

Don't suspend or hibernate when there are 3D resources active since we
can't restore the device's 3D state. Instead fail with an error message.

In other cases, make sure we re-enable the fifo and unlock ttm on resume.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>